It's the second coaster ride closed after El Toro closed in August, also due to a malfunction. El Torro is set to reopen on Saturday, June 17.
Kingda Ka, which is 456 feet high, has been shut down since June 5 after suffering an apparent unintended rollback.
The malfunction involved "a mechanical failure of a component of the launch system during the launch of one of the trains," a state official said. No injuries were reported.
Tammori Petty-Dixon, a spokeswoman with the New Jersey Department of Community Affairs, said the ride has been closed and is under an active investigation.
"Due to this failure during launch, the train did not accelerate to the adequate speed to transition over the apex and returned back through the launch track and to the load/unload station for evacuation," Petty-Dixon said.
The state is consulting with the ride manufacturer "to identify and evaluate the specific component(s) involved in the failure, and to determine the cause of the failure," Petty-Dixon said.
A Six Flags spokeswoman said Kinga Ka is closed for maintenance.
“The ride will reopen soon after its state inspection which is scheduled to happen following this weekend and the Juneteenth holiday on Monday,” park spokeswoman Staci Wheeler said.
Earlier this month, Wheeler said that El Toro was expected to reopen soon.
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